TWI478582B - Sound intermediate frequency demodulator and sound intermediate frequency detecting method thereof - Google Patents
Sound intermediate frequency demodulator and sound intermediate frequency detecting method thereof Download PDFInfo
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本發明是有關於一種解調器及其信號檢測方法，且特別是有關於一種聲音中頻(sound intermediate frequency,sound-IF)的解調器及其聲音中頻的來測方法。The present invention relates to a demodulator and a signal detecting method thereof, and more particularly to a sound intermediate frequency (sound-IF) demodulator and a method for measuring the sound intermediate frequency thereof.
一般而言，各國的電視系統會指定超高頻(ultra high frequency,UHF)或特高頻(Very High Frequency,VHF)頻段的頻道數，其中一個頻道實際上會由兩個信號所組成。一個是圖像信號，其利用對一頻率進行振幅調變(amplitude modulation,AM)來傳送圖像資訊。另一個是聲音信號，其利用對一頻率進行頻率調變(frequency modulation,FM)來傳送聲音資訊，其中聲音信號的頻率與圖像信號的頻率相差一固定位移量，而此固定位移量一般為4.5、5.5、6或6.5MHz。In general, national television systems specify the number of channels in the ultra high frequency (UHF) or Very high frequency (VHF) bands, one of which actually consists of two signals. One is an image signal that utilizes amplitude modulation (AM) for a frequency to transmit image information. The other is a sound signal, which uses frequency modulation (FM) to transmit sound information, wherein the frequency of the sound signal is different from the frequency of the image signal by a fixed amount of displacement, and the fixed displacement is generally 4.5, 5.5, 6 or 6.5 MHz.
在類比電視的應用上，一個調變器選擇一個頻道，並且對此頻道的信號的頻率位移一個固定的中頻(intermediate frequency,IF)。接著，此中頻信號經由中頻解調器解調為一複合電視影像播送信號(composite video broadcast signal,CVBS)及一聲音信號。此頻率調變聲音信號在當下會經由聲音中頻解調器進行解調及放大，並且用來驅動揚聲器。依據上述，若聲音中頻(sound intermediate frequency,sound-IF)解調器為精確地設定以符合所接收信號的來源的環境，則所接收的信號可以完整地解調。In analog TV applications, a modulator selects a channel and shifts the frequency of the channel's signal by a fixed intermediate frequency (IF). Then, the intermediate frequency signal is demodulated into a composite video broadcast signal (CVBS) and a sound signal via an intermediate frequency demodulator. This frequency modulated sound signal is now demodulated and amplified by a sound intermediate frequency demodulator and used to drive the speaker. According to the above, if the sound intermediate frequency (sound-IF) demodulator is accurately set to conform to the source of the received signal, the received signal can be completely demodulated.
然而，由於來源環境的改變，使得聲音中頻解調器的設定可能會不符合來源信號的工作條件。例如以中國的電視節目為例，商業性節目的調變信號的頻率偏移可能兩倍於一般性節目。在此情況之下，若聲音中頻解調器是設定以符合一般性節目，則使用者在商業時段須忍受由於錯誤設定所造成的影響。或者，若聲音中頻解調器提供一保守設定，則使用者須犧牲部份節目的視聽效果。However, due to changes in the source environment, the settings of the sound IF demodulator may not meet the operating conditions of the source signal. For example, in China's television programs, the frequency shift of the modulated signal of a commercial program may be twice that of a general program. In this case, if the sound IF demodulator is set to conform to the general program, the user has to endure the influence due to the erroneous setting during the commercial period. Alternatively, if the sound IF demodulator provides a conservative setting, the user must sacrifice the audiovisual effects of some of the programs.
此外，來源的環境可能改變為單音調頻(FM-mono)、A2、納坎系統(near instantaneous companded audio complex,NICAM)其中之一。並且，電視系統的B/G信號及D/K信號皆能透過以上述三種方法的其中之一傳送。來源的環境可能於聲音中頻解調器設定之後改變，對應於當下來源的環境，聲音中頻解調器可能提供錯誤的設定。In addition, the source environment may be changed to one of the FM-mono, A2, and near instantaneous companded audio complex (NICAM). Moreover, the B/G signal and the D/K signal of the television system can be transmitted through one of the above three methods. The source environment may change after the sound IF demodulator is set, and the sound IF demodulator may provide incorrect settings corresponding to the current source environment.
本發明提供一種聲音中頻解調器及其聲音中頻檢測方法，可以在不用增加額外的硬體的情況下，在不符合的設定下重新設置為符合的設定。The invention provides a sound intermediate frequency demodulator and a sound intermediate frequency detecting method thereof, which can be reset to a matching setting under a non-conforming setting without adding additional hardware.
本發明提出一種聲音中頻解調器，此聲音中頻解調器適用於類比電視系統，並且接收具有第一載波信號及第二載波信號至少其一的聲音信號。類比電視系統的聲音反矩陣運算(de-Matrix)單元適用於對聲音中頻解調器的輸出進行反矩陣運算以產生驅動信號。第一解調單元用以對第一載波信號進行解調以產生第一解調信號至聲音反矩陣運算單元。第二解調單元用以檢測聲音信號的信號品質，並且對第二載波信號進行解調以產生第二解調信號至聲音反矩陣運算單元及/或第一解調單元。當第二解調單元閒置時，第二解調單元被程式化以依據聲音信號的信號品質在聲音信號相關的多個預設標準中選擇一對應的標準，以致於聲音中頻解調器被程式化以對應的標準對聲音信號進行解調。The present invention provides a sound intermediate frequency demodulator suitable for use in an analog television system and for receiving a sound signal having at least one of a first carrier signal and a second carrier signal. The de-Matrix unit of the analog television system is adapted to perform an inverse matrix operation on the output of the sound intermediate frequency demodulator to generate a drive signal. The first demodulation unit is configured to demodulate the first carrier signal to generate a first demodulated signal to the sound inverse matrix operation unit. The second demodulation unit is configured to detect a signal quality of the sound signal, and demodulate the second carrier signal to generate a second demodulated signal to the sound inverse matrix operation unit and/or the first demodulation unit. When the second demodulation unit is idle, the second demodulation unit is programmed to select a corresponding standard among the plurality of preset standards related to the sound signal according to the signal quality of the sound signal, so that the sound intermediate frequency demodulator is Stylization demodulates the sound signal with the corresponding standard.
本發明另提出一種聲音中頻解調器的聲音中頻檢測方法。此聲音中頻檢測方法包括下列步驟：接收具有第一載波信號及第二載波信號至少其一的聲音信號，檢測聲音信號的信號品質；以及，當信號品質符合一閒置條件時，依據聲音信號的信號品質在聲音信號相關的多個預設標準中選擇對應的標準，以致於聲音中頻解調器被程式化以對應的標準對聲音信號進行解調。The invention further provides a sound intermediate frequency detection method for a sound intermediate frequency demodulator. The sound intermediate frequency detecting method comprises the steps of: receiving a sound signal having at least one of a first carrier signal and a second carrier signal, detecting a signal quality of the sound signal; and, when the signal quality meets an idle condition, according to the sound signal The signal quality selects a corresponding standard among a plurality of preset standards related to the sound signal, so that the sound intermediate frequency demodulator is programmed to demodulate the sound signal by a corresponding standard.
在聲音中頻解調器中，提供一種適當的聲音中頻檢測方法。閒置的第二解調單元被程式化以檢測該使用哪一個聲音信號相關的標準，因此聲音中頻解調器被程式化以利用對應的標準對聲音信號進行解調。同時，在對應檢測模式進行時，第二解調單元耦接至第一解調單元及反矩陣運算單元的聲音路徑會被切斷。因此，在第一解調單元進行解調時，不會因閒置的第二解調單元進行檢測而受到影響。藉此，聲音中頻解調器可以在不用增加額外的硬體的情況下，在不符合的設定下重新設置為符合的設定，進一步來說，可以省略進行檢測的額外成本。In a sound intermediate frequency demodulator, an appropriate sound intermediate frequency detection method is provided. The idle second demodulation unit is programmed to detect which of the sound signal correlation criteria is used, so the sound intermediate frequency demodulator is programmed to demodulate the sound signal using the corresponding standard. At the same time, when the corresponding detection mode is performed, the sound path of the second demodulation unit coupled to the first demodulation unit and the inverse matrix operation unit is cut off. Therefore, when the first demodulation unit performs demodulation, it is not affected by the detection by the idle second demodulation unit. Thereby, the sound intermediate frequency demodulator can be reset to the matching setting under the non-conforming setting without adding additional hardware, and further, the additional cost of detecting can be omitted.
為讓本發明之上述特徵和優點能更明顯易懂，下文特舉實施例，並配合所附圖式作詳細說明如下。The above described features and advantages of the present invention will be more apparent from the following description.
以下的敘述將伴隨著實施例的圖示，來詳細對本發明所提出之實施例進行說明。在各圖示中所使用相同或相似的參考標號，是用來敘述相同或相似的部份。The embodiments described below will be described in detail with reference to the drawings of the embodiments. The same or similar reference numerals are used in the drawings to describe the same or similar parts.
圖1為依據本發明一實施例的類比電視聲音中頻(sound intermediate frequency,sound-IF)解調器的系統方塊圖。請參照圖1，在本實施例中，聲音中頻解調器100包括類比解調器110及120及納坎系統(near instantaneous companded audio complex,NICAM)數位解調器130。在本實施例中，為了成本問題，聲音中頻解調器的類比解調器110及120可以使用最簡易的類比解調器。1 is a system block diagram of an analog television intermediate frequency (sound-IF) demodulator according to an embodiment of the invention. Referring to FIG. 1, in the present embodiment, the audio intermediate frequency demodulator 100 includes analog demodulators 110 and 120 and a near instantaneous companded audio complex (NICAM) digital demodulator 130. In this embodiment, the analog demodulator 110 and 120 of the sound intermediate frequency demodulator can use the simplest analog demodulator for cost reasons.
具體來說，聲音中頻解調器100適於接收聲音信號SIF。一般而言，聲音信號SIF具有主載波信號及副載波信號，其中主載波信號是關於基本聲音資訊，副載波信號是除了關於主載波信號相關的聲音資訊外的其他聲音資訊(例如雙語播送或立體聲)。舉例來說，在A2立體聲系統中，聲音信號SIF具有類比主載波信號及類比副載波信號，但在納坎立體聲系統中，聲音信號SIF具有類比主載波信號及數位副載波信號。值得注意的是，利用單音調頻(FM-mono)傳送的聲音信號SIF僅僅具有類比主載波信號而無任何副載波信號。In particular, the sound intermediate frequency demodulator 100 is adapted to receive the sound signal SIF. In general, the sound signal SIF has a primary carrier signal and a subcarrier signal, wherein the primary carrier signal is related to basic sound information, and the secondary carrier signal is other sound information than the sound information related to the primary carrier signal (eg, bilingual broadcast or stereo) ). For example, in an A2 stereo system, the sound signal SIF has an analog primary carrier signal and an analog subcarrier signal, but in a nanocan stereo system, the sound signal SIF has an analog primary carrier signal and a digital subcarrier signal. It is worth noting that the sound signal SIF transmitted using the FM-mono only has an analog primary carrier signal without any subcarrier signals.
當聲音中頻解調器100接收到聲音信號SIF時，主載波信號會經由類比解調器110解調，並據此產生第一解調信號(未繪示)至聲音反矩陣運算單元140。同時，依據副載波信號的格式(例如類比或數位)，副載波信號會經由類比解調器120或納坎系統數位解調器130解調。也就是說，當副載波信號格式是類比時，副載波信號會經由類比解調器120解調，並且解調所產生的第二解調信號(未繪示)透過聲音路徑P1傳送至抽取器(decimator)116。另外，當副載波信號格式為數位時，副載波信號會經由納坎系統數位解調器130解調。在解調之後，解調後的第二解調信號(未繪示)會立即產生並經由聲音路徑P2傳送至聲音反矩陣運算單元140。因此，在副載波信號經類比解調器120或納坎系統數位解調器130解調之後，第二解調信號會對應的輸出至抽取器116或聲音反矩陣運算單元140。在其他實施例中，第二解調信號可以依據聲音中頻解調器的設計而輸出至抽取器116及聲音反矩陣運算單元140。When the sound intermediate frequency demodulator 100 receives the sound signal SIF, the primary carrier signal is demodulated via the analog demodulator 110, and a first demodulated signal (not shown) is generated therefrom to the sound inverse matrix operation unit 140. At the same time, depending on the format of the subcarrier signal (eg, analog or digital), the subcarrier signal is demodulated via analog demodulator 120 or nanokan system digital demodulator 130. That is, when the subcarrier signal format is analogous, the subcarrier signal is demodulated via the analog demodulator 120, and the second demodulated signal (not shown) generated by the demodulation is transmitted to the decimator through the sound path P1. (decimator) 116. Additionally, when the subcarrier signal format is digital, the subcarrier signal is demodulated via the Nakan system digital demodulator 130. After demodulation, the demodulated second demodulated signal (not shown) is immediately generated and transmitted to the sound inverse matrix operation unit 140 via the sound path P2. Therefore, after the subcarrier signal is demodulated by the analog demodulator 120 or the nanokan system digital demodulator 130, the second demodulated signal is output to the decimator 116 or the sound inverse matrix operation unit 140 correspondingly. In other embodiments, the second demodulated signal may be output to the decimator 116 and the sound inverse matrix operation unit 140 in accordance with the design of the sound intermediate frequency demodulator.
在類比解調器110中，所接收到的主載波信號首先經由複數濾波器112過濾，並且複數濾波器112輸出對應主載波信號的過濾結果。接著，零中頻(Zero-IF)解調器114接收經過濾的主載波信號，並且將經過濾的主載波信號轉變為對應於基頻的零中頻信號。之後，零中頻信號經抽取器116處理後輸出至聲音反矩陣運算單元140。據此，聲音反矩陣140輸出對應的驅動信號(包括輸出信號L及R)以驅動揚聲器(未繪示)。In the analog demodulator 110, the received primary carrier signal is first filtered via a complex filter 112, and the complex filter 112 outputs a filtered result corresponding to the primary carrier signal. Next, a zero intermediate frequency (Zero-IF) demodulator 114 receives the filtered primary carrier signal and converts the filtered primary carrier signal to a zero intermediate frequency signal corresponding to the fundamental frequency. Thereafter, the zero intermediate frequency signal is processed by the decimator 116 and output to the sound inverse matrix operation unit 140. Accordingly, the sound inverse matrix 140 outputs corresponding drive signals (including the output signals L and R) to drive speakers (not shown).
同樣地，所接收到的副載波信號經類比解調器120或納坎系統數位解調器130及聲音反矩陣運算單元140處理後，副載波信號被解調、放大且用以驅動揚聲器。值得一提的是，由於在經類比解調器120處理後，經處理的副載波信號(亦即第二解調信號)會輸出至抽取器116，以致於第二解調信號也會經抽取器116處理。因此，抽取器116輸出的第一解調信號更包括所接收的副載波的資訊。Similarly, after the received subcarrier signal is processed by the analog demodulator 120 or the nanokan system digital demodulator 130 and the sound inverse matrix operation unit 140, the subcarrier signal is demodulated, amplified, and used to drive the speaker. It is worth mentioning that, after being processed by the analog demodulator 120, the processed subcarrier signal (i.e., the second demodulated signal) is output to the decimator 116, so that the second demodulated signal is also extracted. Processor 116 processes. Therefore, the first demodulated signal output by the decimator 116 further includes information of the received subcarriers.
在本實施例中，微處理器150會依據副載波信號格式控制複數濾波器122進行切換，以切換複數濾波器122處理類比副載波信號或數位副載波信號。本領域通常知識者可自行理解聲音中頻解調器100的運作原理，故在此不細述聲音中頻解調器100進行解調的運作。In this embodiment, the microprocessor 150 controls the complex filter 122 to switch according to the subcarrier signal format to switch the complex filter 122 to process the analog subcarrier signal or the digital subcarrier signal. Those skilled in the art can understand the operation principle of the sound intermediate frequency demodulator 100, and therefore the operation of the sound intermediate frequency demodulator 100 for demodulation is not described herein.
一般而言，當電視被打開，則首先會掃描每一個頻道，以致於對應各頻道的來源的環境會記錄於電視中。因此，當電視切換至其中一個頻道時，電視會對應來源的環境進行設定。若聲音中頻解調器100被精確設定至符合來源的環境時(例如單音調頻、A2或納坎系統)，所接收到的聲音信號SIF會被完整解調。反之，則僅僅類比解調器110會運作，並且類比解調器120及納坎系統數位解調器130會閒置或進行無義意的作動。據此，依據本發明的一實施例，提供一種適當的聲音中頻檢測方法以應用於聲音中頻解調器。並且，當聲音中頻解調器100的設定不符合來源的環境時，圖1中的聲音路徑P1及P2會切斷，以便於進行聲音中頻檢測方法。同時，運作的類比解調器110仍持續運作。聲音中頻解調器的配置如圖2所示。In general, when the television is turned on, each channel is scanned first, so that the environment corresponding to the source of each channel is recorded on the television. Therefore, when the TV is switched to one of the channels, the TV will be set corresponding to the source environment. If the sound IF demodulator 100 is accurately set to match the source environment (eg, mono tone, A2 or Nakan system), the received sound signal SIF will be fully demodulated. Conversely, only the analog demodulator 110 will operate, and the analog demodulator 120 and the nanokan system digital demodulator 130 will idle or perform unintentional actuation. Accordingly, in accordance with an embodiment of the present invention, an appropriate sound intermediate frequency detection method is provided for use in a sound intermediate frequency demodulator. Moreover, when the setting of the sound intermediate frequency demodulator 100 does not conform to the environment of the source, the sound paths P1 and P2 in FIG. 1 are cut off to facilitate the sound intermediate frequency detecting method. At the same time, the operational analog demodulator 110 continues to operate. The configuration of the sound IF demodulator is shown in Figure 2.
圖2為依據本發明另一實施例的類比電視聲音中頻解調器的系統方塊圖。請參照圖2，在本實施例中，聲音中頻解調器包括與主載波信號相關的第一解調單元210(如圖1的類比解調器110)，以及與副載波相關的第二解調單元220(如圖1的類比解調器120及納坎系統數位解調器130，其中切斷的聲音路徑P1及P2如虛線所示)。一般而言，第二解調單元220耦接至第一解調單元210，並且聲音中頻解調器200配置如圖1的聲音中頻解調器100。當聲音中頻解調器的設定不符合來源的環境時，第二解調單元220會閒置或無義意的作動。此時，聲音路徑P1及P2會切斷，並且第二解調單元220會程式化為副載波檢測模式或高偏移量(high deviation,HDEV)檢測模式(例如頻率偏移)，以便於進行聲音中頻檢測方法。因此，聲音中頻解調器200會程式化以依據副載波檢測模式或高偏移量檢測模式的檢測結果，利用對應的標準(例如單音調頻、A2或納坎系統)對聲音信號進行解調，並且切斷第二解調單元220分別耦接至第一解調單元210及聲音反矩陣運算單元240的聲音路徑P1及P2，其中聲音反矩陣運算單元240輸出對應的驅動信號(包括輸出信號L及R)來驅動揚聲器(未繪示)。據此，聲音中頻解調器200經由第二解調單元220進行聲音中頻檢測方法，由不符合的設定中重新設置為符合的設定。也就是說，聲音中頻解調器可以不須增加額外的硬體，即可由不符合的設定中重新設置為符合的設定。聲音中頻檢測方法具體描述於稍後說明。2 is a system block diagram of an analog television sound IF demodulator in accordance with another embodiment of the present invention. Referring to FIG. 2, in the embodiment, the sound intermediate frequency demodulator includes a first demodulation unit 210 (such as the analog demodulator 110 of FIG. 1) associated with the primary carrier signal, and a second associated with the subcarrier. Demodulation unit 220 (such as analog demodulator 120 of FIG. 1 and nano-campus digital demodulator 130, wherein the cut-off sound paths P1 and P2 are shown by dashed lines). In general, the second demodulation unit 220 is coupled to the first demodulation unit 210, and the sound intermediate frequency demodulator 200 is configured with the sound intermediate frequency demodulator 100 of FIG. When the setting of the sound intermediate frequency demodulator does not conform to the source environment, the second demodulation unit 220 may be idle or unintentional. At this time, the sound paths P1 and P2 are cut off, and the second demodulation unit 220 is programmed into a subcarrier detection mode or a high deviation (HDEV) detection mode (for example, a frequency offset) to facilitate the operation. Sound intermediate frequency detection method. Therefore, the sound intermediate frequency demodulator 200 is programmed to solve the sound signal according to the detection result of the subcarrier detection mode or the high offset detection mode by using a corresponding standard (for example, monophonic frequency modulation, A2 or Nakan system). The second demodulation unit 220 is coupled to the sound paths P1 and P2 of the first demodulation unit 210 and the sound inverse matrix operation unit 240, wherein the sound inverse matrix operation unit 240 outputs a corresponding drive signal (including the output). Signals L and R) drive the speakers (not shown). Accordingly, the sound intermediate frequency demodulator 200 performs the sound intermediate frequency detecting method via the second demodulating unit 220, and is reset to the matching setting by the non-compliant setting. In other words, the sound IF demodulator can be reset to a matching setting from a non-compliant setting without adding additional hardware. The sound intermediate frequency detecting method is specifically described later.
圖3及圖4分別為依據本發明一實施例的應用於聲音中頻解調器的聲音中頻檢測方法的副載波檢測模式及高偏移量檢測模式的流程圖。請參照圖2至圖4，在本實施例中，第一測試單元260會程式化以執行副載波檢測模式，並且第二測試單元270會程式化以執行高偏移量檢測模式。如圖2所示，第一測試單元260為零中頻解調器224，並且第二測試單元270包括微分四相移鍵控(Differential Quadrature Phase Shift Keying,DQPSK)解碼器234及納坎系統解框器(Deframer)236。值得一提的是，第一測試單元260及第二測試單元在本實施例為用以說明，但並非以此限制本發明。3 and FIG. 4 are flowcharts showing a subcarrier detection mode and a high offset detection mode of a sound intermediate frequency detection method applied to a sound intermediate frequency demodulator according to an embodiment of the invention. Referring to FIG. 2 to FIG. 4, in the embodiment, the first test unit 260 is programmed to perform the subcarrier detection mode, and the second test unit 270 is programmed to perform the high offset detection mode. As shown in FIG. 2, the first test unit 260 is a zero intermediate frequency demodulator 224, and the second test unit 270 includes a Differential Quadrature Phase Shift Keying (DQPSK) decoder 234 and a Nakan system solution. A framer (Deframer) 236. It is to be noted that the first test unit 260 and the second test unit are used in the present embodiment for illustration, but are not intended to limit the present invention.
請參照圖2及圖3，在副載波檢測模式中，當聲音中頻解調器200為設定利用A2標準對聲音信號SIF進行解調時(步驟S301)，第一測試單元260會程式化以檢測副載波信號(步驟S302)。因此，第一測試單元260會程式化以判斷副載波信號的信號品質(例如信雜比)是否大於第一信號品質臨界值(步驟S302)。若副載波信號的信號品質大於第一信號品質臨界值(步驟S302)，代表不用進行副載波檢測模式，則副載波檢測模式在此執行期間中休眠(步驟S300)。Referring to FIG. 2 and FIG. 3, in the subcarrier detection mode, when the audio intermediate frequency demodulator 200 is configured to demodulate the sound signal SIF by using the A2 standard (step S301), the first test unit 260 is programmed to The subcarrier signal is detected (step S302). Therefore, the first test unit 260 is programmed to determine whether the signal quality (eg, the signal-to-noise ratio) of the subcarrier signal is greater than the first signal quality threshold (step S302). If the signal quality of the subcarrier signal is greater than the first signal quality threshold (step S302), it means that the subcarrier detection mode is not performed, and the subcarrier detection mode is dormant during this execution period (step S300).
另一方面，當聲音中頻解調器200為設定利用納坎系統標準對聲音信號SIF進行解調時(步驟S301)，第二測試單元270會程式化以檢測副載波信號(步驟S303)。因此，第二測試單元270會程式化以判斷副載波信號的位元錯誤率(bit error rate,BER)是否小於第一位元錯誤率臨界值(步驟S303)。同樣地，若副載波信號的位元錯誤率小於第一位元錯誤率臨界值(步驟S303)，也代表不用進行副載波檢測模式，以致於副載波模式在執行期間中休眠(步驟S300)。在本實施例中，副載波檢測模式不須持續進行，並且聲音中頻檢測方法在需要時選擇性的執行。On the other hand, when the sound intermediate frequency demodulator 200 sets the demodulation of the sound signal SIF using the Nakan system standard (step S301), the second test unit 270 is programmed to detect the subcarrier signal (step S303). Therefore, the second test unit 270 is programmed to determine whether the bit error rate (BER) of the subcarrier signal is less than the first bit error rate threshold (step S303). Similarly, if the bit error rate of the subcarrier signal is smaller than the first bit error rate threshold (step S303), it also means that the subcarrier detection mode is not performed, so that the subcarrier mode is dormant during execution (step S300). In the present embodiment, the subcarrier detection mode does not have to be continued, and the sound intermediate frequency detection method is selectively performed as needed.
此外，若副載波信號的信號品質小於第一信號品質臨界值(步驟302)，或者副載波信號的位元錯誤率大於第一位元錯誤率臨界值(步驟303)，則聲音路徑P1及P2會切斷(步驟S304)。接著，第二解調單元220會受控於微處理器250而程式化為依據A2標準進行測試(步驟S305)。在本實施例中，複數濾波器222及零中步解調器224(亦即第一測試單元260)為僅僅程式化為依據A2標準進行測試。複數濾波器222為程式化以過濾類比副載波信號。In addition, if the signal quality of the subcarrier signal is less than the first signal quality threshold (step 302), or the bit error rate of the subcarrier signal is greater than the first bit error rate threshold (step 303), the sound paths P1 and P2 It will be cut off (step S304). Next, the second demodulation unit 220 is controlled by the microprocessor 250 to be programmed to test according to the A2 standard (step S305). In the present embodiment, the complex filter 222 and the zero mid-step demodulator 224 (i.e., the first test unit 260) are only programmed to be tested in accordance with the A2 standard. Complex filter 222 is programmed to filter the analog subcarrier signals.
舉例來說，當聲音中頻解調器200設定以A2標準對聲音信號SIF進行解調(步驟S301)，而第二解調單元220卻接收到為納坎系統標準的數位副載波信號。為納坎系統標準的數位副載波的信號品質自然會小於第一信號品質臨界值(步驟S302)。據此，聲音路徑P1及P2會被切斷(步驟S304)，且進一步進行A2標準的測試(步驟S305)。此時，由於聲音路徑P1及P2被切斷，所以運作中的第一解調單元210會持續運作而不會受到第二解調單元220的影響。For example, when the sound intermediate frequency demodulator 200 is set to demodulate the sound signal SIF by the A2 standard (step S301), the second demodulation unit 220 receives the digital subcarrier signal which is a standard of the Nakan system. The signal quality of the digital subcarriers that are standard for the Nakan system is naturally smaller than the first signal quality threshold (step S302). According to this, the sound paths P1 and P2 are cut off (step S304), and the A2 standard test is further performed (step S305). At this time, since the sound paths P1 and P2 are cut off, the first demodulation unit 210 in operation continues to operate without being affected by the second demodulation unit 220.
請參照圖2及圖3，當第一測試單元260受控於微處理器250而程式化為依據A2標準進行測試(步驟S305)，第一測試單元260會判斷副載波信號的信號品質是否大於第二信號品質臨界值(步驟S306)，其中第二信號品質臨界值可以大於第一信號品質臨界值。若副載波信號的信號品質大於第二信號品質臨界值(步驟S306)，代表已確認副載波信號為A2標準，並且進一步聲音中頻解調器200會被程式化以符合A2標準(步驟S307)。據此，被切斷的第二解調單元220的聲音路徑P1及P2會再分別連接至第一解調單元210及聲音反矩陣運算單元240(步驟S311)，以致於聲音中頻解調器200配置如圖1的聲音中頻解調器100。接著，副載波檢測模式在此執行期間中休眠(步驟S300)。Referring to FIG. 2 and FIG. 3, when the first test unit 260 is controlled by the microprocessor 250 and programmed to test according to the A2 standard (step S305), the first test unit 260 determines whether the signal quality of the subcarrier signal is greater than or equal to a second signal quality threshold (step S306), wherein the second signal quality threshold may be greater than the first signal quality threshold. If the signal quality of the subcarrier signal is greater than the second signal quality threshold (step S306), the acknowledged subcarrier signal is the A2 standard, and the further audio intermediate frequency demodulator 200 is programmed to conform to the A2 standard (step S307). . Accordingly, the sound paths P1 and P2 of the cut second demodulation unit 220 are again connected to the first demodulation unit 210 and the sound inverse matrix operation unit 240, respectively (step S311), so that the sound intermediate frequency demodulator 200 is configured as the sound intermediate frequency demodulator 100 of FIG. Next, the subcarrier detection mode sleeps during this execution (step S300).
另一方面，若副載波信號的信號品質小於第二信號品質臨界值(步驟S306)，第二解調單元220會受控於微處理器250而程式化為依據納坎系統標準進行測試(步驟S308)。在本實施例中，複數濾波器222、符元時序取得單元232、微分四相移鍵控(DQPSK)解碼器234及納坎系統解框器236會僅僅程式化以依據納坎系統標準進行測試。複數濾波器222受控於微處理器250進行切換以過濾數位副載波信號。當第二測試單元270(亦即微分四相移鍵控解碼器234及納坎系統解框器236)受控於微處理器250而程式化以依據納坎系統標準進行測試(步驟308)，第二測試單元270會判斷副載波信號的位元錯誤率是否小於第二位元錯誤率臨界值(步驟S309)。若副載波信號的位元錯誤率小於第二位元錯誤率臨界值(步驟S309)，代表已確認副載波信號為納坎系統標準，並且進一步聲音中頻解調器200會被程式化以符合納坎系統標準(步驟S310)。據此，被切斷的第二解調單元220的聲音路徑P1及P2會再分別連接第一解調單元210及聲音反矩陣運算單元240(步驟S311)，以致於聲音中頻解調器200配置如圖1的聲音中頻解調器100。接著，副載波檢測模式在此執行期間中休眠(步驟S300)。在本實施例中，第二位元錯誤率臨界值小於第一位元錯誤率臨界值，以致於能夠確實確認副載波信號為納坎系統標準。On the other hand, if the signal quality of the subcarrier signal is less than the second signal quality threshold (step S306), the second demodulation unit 220 is controlled by the microprocessor 250 and programmed to test according to the Nakan system standard (steps) S308). In this embodiment, the complex filter 222, the symbol timing acquisition unit 232, the differential quadrature phase shift keying (DQPSK) decoder 234, and the Nakan system deblocker 236 are only programmed to test according to the Nakan system standard. . Complex filter 222 is controlled by microprocessor 250 to switch to filter the digital subcarrier signals. When the second test unit 270 (ie, the differential quadrature shift keying decoder 234 and the Nakan system deframer 236) is controlled by the microprocessor 250 to be programmed to test according to the Nakan system standard (step 308), The second test unit 270 determines whether the bit error rate of the subcarrier signal is less than the second bit error rate threshold (step S309). If the bit error rate of the subcarrier signal is less than the second bit error rate threshold (step S309), it represents that the confirmed subcarrier signal is a Nakan system standard, and further the sound intermediate frequency demodulator 200 is programmed to conform Nakan system standard (step S310). Accordingly, the sound paths P1 and P2 of the cut second demodulation unit 220 are connected to the first demodulation unit 210 and the sound inverse matrix operation unit 240, respectively (step S311), so that the sound intermediate frequency demodulator 200 The sound intermediate frequency demodulator 100 of FIG. 1 is configured. Next, the subcarrier detection mode sleeps during this execution (step S300). In this embodiment, the second bit error rate threshold is less than the first bit error rate threshold so that the subcarrier signal can be reliably confirmed as the Nakan system standard.
然而，若副載波信號的位元錯誤率被判斷大於第二位元錯誤率臨界值(步驟S309)，則被程式化以依據納坎系統標準進行測試的第二解調單元220會選擇性的程式化以再次依據A2標準進行測試或停止依據納坎系統標準進行測試。當第二解調單元220程式化以再次依據A2標準進行測試，步驟S305、S306、S308及309的迴圈會再重覆執行。在本實施例中，當步驟S305、S306、S308及309的迴圈再重覆執行時，聲音中頻解調器200可以切換至高偏移量檢測模式。並且，當第二解調單元220被程式化以停止依據納坎系統標準進行測試，被切斷的第二解調單元220的聲音路徑P1及P2會再分別連接至第一解調單元210及聲音反矩陣運算單元240(步驟S311)，以致於聲音中頻解調器200配置如圖1方聲音中頻解調器100。接著，副載波檢測模式在此執行期間中休眠(步驟S300)。However, if the bit error rate of the subcarrier signal is judged to be greater than the second bit error rate threshold (step S309), the second demodulation unit 220 that is programmed to test according to the Nakan system standard is selective. Stylized to test again according to the A2 standard or to stop testing according to the Nakan system standard. When the second demodulation unit 220 is programmed to test again according to the A2 standard, the loops of steps S305, S306, S308, and 309 are repeated again. In the present embodiment, when the loops of steps S305, S306, S308, and 309 are repeatedly executed again, the sound intermediate frequency demodulator 200 can be switched to the high offset detection mode. Moreover, when the second demodulation unit 220 is programmed to stop testing according to the Nakan system standard, the sound paths P1 and P2 of the cut second demodulation unit 220 are respectively connected to the first demodulation unit 210 and The sound inverse matrix operation unit 240 (step S311), so that the sound intermediate frequency demodulator 200 is configured as the side sound intermediate frequency demodulator 100 of FIG. Next, the subcarrier detection mode sleeps during this execution (step S300).
請參照圖2及圖4，在高偏移量檢測模式中，第二解調單元220被程式化為較大的偏移量以評估所接收的聲音信號SIF。在此，第二解調單元220假設為用以估評為單音調頻的聲音信號SIF。在本實施例中，複數濾波器222及零中頻解調器224(亦即第一測試單元260)僅僅被程式化以評估主載波信號的信號品質(例如信雜比)及功率(步驟S401)。同時，複數濾波器222被程式化以過濾類比聲音信號SIF。在步驟S401中，第一測試單元260受控於微處理器250而被程式化來判斷主載波的信號品質是否小於第一信號品質臨界值及主載波的功率是否大於功率臨界值。Referring to FIG. 2 and FIG. 4, in the high offset detection mode, the second demodulation unit 220 is programmed to be a larger offset to evaluate the received sound signal SIF. Here, the second demodulation unit 220 is assumed to be a sound signal SIF for evaluation of monophonic frequency modulation. In the present embodiment, the complex filter 222 and the zero intermediate frequency demodulator 224 (ie, the first test unit 260) are only programmed to evaluate the signal quality (eg, signal-to-noise ratio) and power of the primary carrier signal (step S401). ). At the same time, the complex filter 222 is programmed to filter the analog sound signal SIF. In step S401, the first test unit 260 is controlled by the microprocessor 250 to determine whether the signal quality of the primary carrier is less than the first signal quality threshold and whether the power of the primary carrier is greater than the power threshold.
若主載波的信號品質小於第一信號品質臨界值且主載波的功率大於功率臨界值，代表不用進行高偏移量檢測模式，以致於則高偏移量檢測模式在此執行期間中休眠(步驟S400)。在本實施例中，高偏移量檢測模式不須持續進行，並且聲音中頻檢測方法在需要時選擇性的執行。反之，聲音路徑P1及P2會切斷(步驟S402)，並且進一步第一測試單元260被程式化來進行副載波信號的高偏移量測試(步驟S403)。據此，由於聲音路徑P1及P2被切斷，所以運作中的第一解調單元210會持續運作而不會受到第二解調單元220的影響。If the signal quality of the primary carrier is less than the first signal quality threshold and the power of the primary carrier is greater than the power threshold, it means that the high offset detection mode is not required, so that the high offset detection mode sleeps during this execution (step S400). In the present embodiment, the high offset detection mode does not have to be continued, and the sound intermediate frequency detection method is selectively performed as needed. On the contrary, the sound paths P1 and P2 are cut off (step S402), and further the first test unit 260 is programmed to perform a high offset test of the subcarrier signal (step S403). Accordingly, since the sound paths P1 and P2 are cut off, the first demodulation unit 210 in operation continues to operate without being affected by the second demodulation unit 220.
在步驟S404中，第一測試單元260受控於微處理器而被程式化以判斷副載波的信號品質是否大於第二信號品質臨界值。若副載波的信號品質大於第二信號品質臨界值(步驟S404)，聲音中頻解調器200被程式化為對聲音信號SIF的主載波信號進行高偏移量解調，以及對聲音信號SIF的副載波信號進行納坎系統標準解調(步驟S405)。據此，被切斷的第二解調單元220的聲音路徑P1及P2會再分別連接至第一解調單元210及聲音反矩陣運算單元240(步驟S406)，以致於聲音中頻解調器200配置如圖1的聲音中頻解調器100。接著，高偏移量檢測模式在此執行期間中休眠(步驟S400)。In step S404, the first test unit 260 is controlled by the microprocessor to determine whether the signal quality of the subcarrier is greater than the second signal quality threshold. If the signal quality of the subcarrier is greater than the second signal quality threshold (step S404), the audio intermediate frequency demodulator 200 is programmed to perform high offset demodulation on the primary carrier signal of the sound signal SIF, and to the sound signal SIF The subcarrier signal is subjected to Nakan system standard demodulation (step S405). Accordingly, the sound paths P1 and P2 of the cut second demodulation unit 220 are again connected to the first demodulation unit 210 and the sound inverse matrix operation unit 240, respectively (step S406), so that the sound intermediate frequency demodulator 200 is configured as the sound intermediate frequency demodulator 100 of FIG. Next, the high offset detection mode sleeps during this execution (step S400).
值得注意的是，由於單音調頻的聲音信號SIF僅具有主載波信號而無副載波信號，本實施例的聲音解調器200會預先程式化以納坎系統標準對副載波信號進行解調(步驟S405)。在其他實施例中，聲音中頻解調器200可以預先程式化以A2標準對副載波信號進行解調(步驟S405)。It should be noted that since the monophonic audio signal SIF has only the primary carrier signal and no subcarrier signal, the sound demodulator 200 of the present embodiment pre-programs the subcarrier signal by the Nakan system standard ( Step S405). In other embodiments, the sound intermediate frequency demodulator 200 can be pre-programmed to demodulate the subcarrier signal by the A2 standard (step S405).
然而，若副載波信號的信號品質被判斷小於第二信號品質臨界值(步驟S404)，被程式化以高偏移量測試的第二解調單元220會選擇性被程式化以在此執行期間中休眠或停止高偏移量測試。當第二解調單元200被程式化以停止高偏移量測試時，被切斷的第二解調單元220的聲音路徑P1及P2會再分別連接至第一解調單元210及聲音反矩陣運算單元240(步驟S406)，以致於聲音中頻解調器200配置如圖1的聲音中頻解調器100。接著，高偏移量檢測模式在此執行期間中休眠(步驟S400)。此外，當第二解調單元200被程式化以在此執行期間中休眠時(步驟S407)，步驟S404、S407及403的迴圈在稍後會再重覆執行。在本實施例中，當步驟S404、S407及403的迴圈重覆執行時，聲音中頻解調器200可以切換至副載波檢測模式。However, if the signal quality of the subcarrier signal is judged to be smaller than the second signal quality threshold (step S404), the second demodulation unit 220 programmed to be tested with a high offset is selectively programmed to be executed during this execution. Sleep or stop high offset test. When the second demodulation unit 200 is programmed to stop the high offset test, the sound paths P1 and P2 of the cut second demodulation unit 220 are again connected to the first demodulation unit 210 and the sound inverse matrix, respectively. The arithmetic unit 240 (step S406), so that the sound intermediate frequency demodulator 200 is configured with the sound intermediate frequency demodulator 100 of FIG. Next, the high offset detection mode sleeps during this execution (step S400). Further, when the second demodulation unit 200 is programmed to sleep during this execution (step S407), the loops of steps S404, S407, and 403 are repeatedly executed later. In the present embodiment, when the loops of steps S404, S407, and 403 are repeatedly executed, the sound intermediate frequency demodulator 200 can switch to the subcarrier detection mode.
綜上所述，依據上述實施例的描述，本發明提供一種聲音中頻解調器的聲音中頻檢測方法。閒置的硬體(如第二解調單元)在聲音中頻解調器的設定與所接收的聲音信號(音頻信號)不符合時，閒置的硬體會被程式化以檢測聲音信號以什麼標準所傳送的，以便於聲音中頻解調器依據檢測結果而被程式化為利用對應的標準對聲音信號進行解調。同時，在執行對應的檢測模式時，第二解調單元分別耦接至第一解調單元及聲音反矩陣運算單元的聲音路徑會切斷。據此，第一解調單元在進行解調時不會受到第二解調單元進行檢測而有所影響。藉此，聲音中頻解調器可以在不用增加額外的硬體的情況下，在不符合的設定下重新設置為符合的設定，並且進一步可省略進行檢測的額外成本。In summary, according to the description of the above embodiments, the present invention provides a sound intermediate frequency detection method for a sound intermediate frequency demodulator. The idle hardware (such as the second demodulation unit), when the setting of the sound intermediate frequency demodulator does not match the received sound signal (audio signal), the idle hardware is programmed to detect the standard of the sound signal. Transmitted so that the sound IF demodulator is programmed according to the detection result to demodulate the sound signal using the corresponding standard. At the same time, when the corresponding detection mode is executed, the sound path of the second demodulation unit coupled to the first demodulation unit and the sound inverse matrix operation unit is cut off. Accordingly, the first demodulation unit is not affected by the detection by the second demodulation unit when performing demodulation. Thereby, the sound intermediate frequency demodulator can be reset to the matching setting at a non-conforming setting without adding additional hardware, and the additional cost of detecting can be further omitted.
雖然本發明已以實施例揭露如上，然其並非用以限定本發明，任何所屬技術領域中具有通常知識者，在不脫離本發明之精神和範圍內，當可作些許之更動與潤飾，故本發明之保護範圍當視後附之申請專利範圍所界定者為準。Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.
100、200．．．聲音中頻解調器100, 200. . . Sound IF demodulator
110、120．．．類比解調器110, 120. . . Analog demodulator
112、122、212、222．．．複數濾波器112, 122, 212, 222. . . Complex filter
114、124、214、224．．．零中頻解調器114, 124, 214, 224. . . Zero IF demodulator
116、216．．．抽取器116,216. . . Extractor
126．．．識別解調器126. . . Identification demodulator
130．．．納坎系統數位解調器130. . . Nakan system digital demodulator
132、232．．．符元時序取得單元132, 232. . . Symbol timing acquisition unit
134、234．．．微分四相移鍵控解碼器134, 234. . . Differential quadrature shift keying decoder
136、236．．．納坎系統解框器136, 236. . . Nakan system deframer
140、240．．．聲音反矩陣運算單元140, 240. . . Sound inverse matrix unit
150、250‧‧‧微處理器150, 250‧‧‧ microprocessor
210‧‧‧第一解調單元210‧‧‧First demodulation unit
220‧‧‧第二解調單元220‧‧‧Second demodulation unit
260‧‧‧第一測試單元260‧‧‧First test unit
270‧‧‧第二測試單元270‧‧‧Second test unit
P1、P2‧‧‧聲音路徑P1, P2‧‧‧ sound path
SIF‧‧‧聲音信號SIF‧‧‧Sound signal
S300~S311‧‧‧本發明一實施例的應用於聲音中頻解調器的聲音中頻檢測方法的副載波檢測模式的各步驟S300~S311‧‧‧ steps of a subcarrier detection mode applied to a sound intermediate frequency detection method of a sound intermediate frequency demodulator according to an embodiment of the present invention
S400~S407‧‧‧本發明一實施例的應用於聲音中頻解調器的聲音中頻檢測方法的高偏移量檢測模式的各步驟S400~S407‧‧‧ steps of a high offset detection mode applied to a sound intermediate frequency detection method of a sound intermediate frequency demodulator according to an embodiment of the present invention
圖1為依據本發明一實施例的類比電視聲音中頻解調器的系統方塊圖。1 is a system block diagram of an analog television sound IF demodulator in accordance with an embodiment of the present invention.
圖2為依據本發明另一實施例的類比電視聲音中頻解調器的系統方塊圖。2 is a system block diagram of an analog television sound IF demodulator in accordance with another embodiment of the present invention.
圖3為依據本發明一實施例的應用於聲音中頻解調器的聲音中頻檢測方法的副載波檢測模式的流程圖。3 is a flow chart of a subcarrier detection mode applied to a sound intermediate frequency detection method of a sound intermediate frequency demodulator according to an embodiment of the invention.
圖4為依據本發明一實施例的應用於聲音中頻解調器的聲音中頻檢測方法的高偏移量檢測模式的流程圖。4 is a flow chart of a high offset detection mode applied to a sound intermediate frequency detection method of a sound intermediate frequency demodulator according to an embodiment of the invention.
200．．．聲音中頻解調器200. . . Sound IF demodulator
212、222．．．複數濾波器212, 222. . . Complex filter
214、224．．．零中頻解調器214, 224. . . Zero IF demodulator
216．．．抽取器216. . . Extractor
232．．．符元時序取得單元232. . . Symbol timing acquisition unit
234．．．微分四相移鍵控解碼器234. . . Differential quadrature shift keying decoder
236．．．納坎系統解框器236. . . Nakan system deframer
240．．．聲音反矩陣運算單元240. . . Sound inverse matrix unit
250．．．微處理器250. . . microprocessor
210．．．第一解調單元210. . . First demodulation unit
220．．．第二解調單元220. . . Second demodulation unit
260．．．第一測試單元260. . . First test unit
270．．．第二測試單元270. . . Second test unit
P1、P2．．．聲音路徑P1, P2. . . Sound path
SIF．．．聲音信號SIF. . . Sound signal
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